import { z } from 'zod';
import type { StorePaths } from '../store/paths.js';
import type { ExecFn } from '../util/exec.js';
/**
 * Checkpoints are commits created with git plumbing through a TEMPORARY
 * index: the user's index, worktree and HEAD are never moved. Each snapshot
 * lands under `refs/nightwatch/<session>` so `git log` stays clean and a
 * normal `git gc` keeps the objects alive while the ref exists.
 */
export declare const checkpointSchema: z.ZodObject<{
    session: z.ZodString;
    seq: z.ZodNumber;
    commit: z.ZodString;
    tree: z.ZodString;
    ts: z.ZodString;
    note: z.ZodOptional<z.ZodString>;
}, "strip", z.ZodTypeAny, {
    seq: number;
    ts: string;
    session: string;
    commit: string;
    tree: string;
    note?: string | undefined;
}, {
    seq: number;
    ts: string;
    session: string;
    commit: string;
    tree: string;
    note?: string | undefined;
}>;
export type Checkpoint = z.infer<typeof checkpointSchema>;
export declare function listCheckpoints(paths: StorePaths, session?: string): readonly Checkpoint[];
export interface CheckpointOutcome {
    readonly created: boolean;
    readonly checkpoint?: Checkpoint;
    readonly reason?: string;
}
export declare function createCheckpoint(paths: StorePaths, projectRoot: string, session: string, note?: string, exec?: ExecFn, now?: () => Date): CheckpointOutcome;
/** Returns the shell command a user should run to restore a checkpoint. */
export declare function restoreCommand(checkpoint: Checkpoint): string;
/**
 * Auto-checkpoint on SessionStart as well as Stop. A single-turn headless run
 * fires Stop only once — at the very end — so without the session-start
 * baseline the scope check would diff against the END state and hide every
 * tracked-file modification. Found by the first recorded self-run.
 */
export declare function isAutoCheckpointEvent(hookEventName: string): boolean;